Startup Gets $10 Million To Pump More Energy Storage Into Texas Grid

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Texas has an electricity grid problem of its own making. Almost the entire grid is walled off from neighboring connections, leaving residents more vulnerable to extended outages like the one happening now. On the bright side, the isolation has motivated grid planners to encourage more in-state wind and solar activity, along with new energy storage systems that save all those clean kilowatts for later use.

The Pumped Hydropower Long Duration Energy Storage Solution

If you’re wondering why not just invest in some more lithium-ion battery arrays to make the Texas grid more resilient, that’s a good question. Li-ion batteries can handle routine grid balancing chores and minor emergencies, but they typically last for just 4-6 hours. In a world where grids are saturated with wind and solar power, the ideal minimum amount of energy storage has been pegged at 10 hours. The US Department of Energy is also among those seeking new technologies that can last days, weeks, or whole seasons.

The Texas startup Quidnet Energy has crossed the Energy Department’s radar with a long duration energy storage solution similar to pumped hydropower systems, but different.

Pumped hydro systems rely on gravity. They use excess wind or solar power to raise water to an elevated level. When electricity is needed, the water is released to a lower level where a generating station is located.

On the down side, pumped hydropower systems require massive and costly new infrastructure along with consequent environmental impacts. They also require specific geography, namely, two different elevations. Quidnet’s solution is to locate the storage reservoir in underground rock formations. In addition to reducing surface infrastructure and impacts, the technology is also landscape-agnostic. It can be deployed wherever the underground rock is suitable, regardless of surface elevation.

When excess wind and solar power are available, the system pushes pressurized water underground. When electricity is needed, the pressure sends water back up to the surface for power generation.

Back in 2019, CleanTechnica took note of an Energy Department award to help Quidnet develop the new system. “The Houston-based company Quidnet Energy Inc. will focus on injecting water under pressure into rock structures,” we observed.

“The innovative technology can operate at higher temperature than traditional PSH, achieve 95% mechanical efficiency (each way), and has the potential to reduce capital expenditures and energy storage solutions in relatively flat areas where conventional PSH may not be possible,” the Energy Department noted.

Investors Finally Notice New Energy Storage System

The 2019 award was just the beginning. In 2022, Quidnet earned funding from the Energy Department’s ARPA-E office, which assists high risk, high reward technologies that private sector investors are too skittish to touch.

The new round of funding was aimed at the scale-up step.

“Quidnet Energy, Inc. (Houston, TX) will scale its Geomechanical Pumped Storage (GPS) to a commercial system at CPS Energy, the largest U.S. municipal utility,” ARPA-E noted. “The objective is to lower cost associated with long-duration energy storage by 50-75% to enable more reliable and cost-effective utilization of renewable electricity generating assets,” they add.

Somewhere along the line Quidnet changed the name of its system to GES, for Geomechanical Energy Storage, and now all that hard work has finally paid off in the form of private sector investment. Thank you, US taxpayers. Give yourself a group hug.

Earlier this week, Quidnet announced that it nailed down a $10 million strategic partnership with the leading energy storage firm Hunt Energy Network. The partners expect the arrangement to yield 300 megawatts’ worth of energy storage projects for Texas.

Specifically, the new projects will be in the service of ERCOT, the Electric Reliability Council of Texas, which is the grid manager responsible for almost the entire state.

“The two companies will work together to address ERCOT’s urgent need for energy storage as the grid operator onboards an increasing number of intermittent renewable assets. The partnership will pair Quidnet’s long-duration energy storage with Hunt Energy Network’s success in developing storage projects and Hunt Energy’s subsurface technologies similar to Quidnet’s GES,” the partners explained in a press statement.

If you caught that thing about Hunt Energy’s subsurface technologies, there are a lot of Hunts floating around in the US oil and gas industry. If you can untangle that, drop us a note in the comment thread. The short version is that the new partnership with Hunt Energy Network enables Quidnet to tap into the knowledge base of an experienced oilfields firm.

More Energy Storage For Texas

Quidnet is not alone. Texas has already emerged as the preferred proving ground for a number of other new underground energy storage technologies.

Last October, the Journal of Petroleum Technology drew attention to Quidnet and another Texas-based firm, Sage Geosystems, which has been leveraging oilfield technology to cut the cost of its geothermal energy and energy storage systems for wind and solar power.

Another interesting technology is Gravity Well, an underground gravity-based energy storage system developed by the startup Renewell, which has offices in Texas and California.

Gravity Well wears two hats. In addition to energy storage, the system provides a financial platform for sealing and monitoring abandoned wells. To pile on the layers of green, Gravity Well also deploys repurposed oilfield supplies and equipment.

“In an ideal world idle wells wouldn’t be plugged and abandoned, they would be plugged and monitored,” Renewell explains. “Not only is a Gravity Well plugged above the depleted reservoir, there is also a suite of sensors on each well ensuring an unprecedented level of insight into its status.”

“Inactive oil and gas wells are an ideal host for gravity energy storage due to their depth, expensive plug and abandonment (P&A), pre-existing electrical infrastructure, and current emissions,” the company adds.

Underground compressed air energy storage is also making an appearance, with the Texas startup Apex-CAES laying plans for a 324-megawatt system in Anderson County. For the record, the company’s investors include the Texas firm Haddington as well as Siemens.

Of course, no mention of underground energy storage in Texas would be complete without a mention of the state’s salt cavern resources, which researchers at the University of Texas say could be used for green hydrogen storage, geothermal projects, and other clean technologies, so stay tuned for more on that.

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Image (cropped): Quidnet Energy deploys underground rock formations for new pumped hydropower energy storage system (courtesy of Quidnet).

For more (much more) CleanTechnica coverage of the goings-on in Texas, go here.